Print hammer recording assembly



Nov. 2, 1965 s. A. UNGMAN PRINT HAMMER RECORDING ASSEMBLY 2 Sheets-Sheet 1 Filed Feb. 18, 1963 INVENTOR,

STE/V A. UNGMA/V BY mm, Mam, falhmua 'h/yM Attorneys Nov. 2, 1965 s. A. UNGMAN 3,215,068

PRINT HAMMER RECORDING ASSEMBLY Filed Feb. 18, 1963 2 Sheets-Sheet 2 INVENTOR .STEN A. UNGMAN BY 7mb, KDIMM fi/AMWMW A Attorneys.

United States Patent PRINT HAMMER RECORDING ASSEMBLY Sten A. Ungnran, Solna, Sweden, assignor to Svenska Dataregister A.B., Solna, Sweden, a corporation of Sweden Filed Feb. 18, 1963, Ser. No. 259,062

Claims priority, application Sweden, Feb. 21, 1962,

12 Claims. (Cl. 101-93) This invention relates to a recording assembly and, more particularly, to an improved hammer means for recording coded data.

The recording units in many different types of accounting machines, such as cash registers and tabulating or adding machines, commonly include type wheels or strips having raised alphabetical and numerical characters against which an inked ribbon and a record medium are forced by a hammer assembly. Since the records produced by these units are usually intended for only visual inspection, the printed characters do not need to be of uniform density or configuration although this would be desirable. Thus, these recording units generally do not require accurate centering and alignment of the type wheels or strips and precise adjustment of the striking angle of the hammer assembly.

The desire for greater speed and accuracy in the collection of data relating to retail sales, for instance, has led to the provision of recording units in equipment located at the point of sale for producing input records for remote accounting equipment that are expressed in a form and language that can be directly utilized in the accounting equipment. As an example, the copending application of Gunner E. Sundblad, Serial No. 171,967, filed February 8, 1962, which application is assigned to the same assignee as the present invention, discloses a recording assembly that can be used in cash registers to produce a printed record expressed in both Arabic characters and a binary bar code. This record can be both visually inspected and sensed by photoelectric means. However, the accuracy and efficiency of the photoelectric reading equipment is substantially enhanced by insuring that the recorded bar code is uniform in density and clear and distinct in outline. This is somewhat difiicult to obtain with conventional hammer constructions because each coded data representing area can include a number of spaced raised portions representing code bits, and the alignment and centering of the coded wheels as well as the strike angle of the hammer must be precisely adjusted to insure the desired clarity of printing. Even if these adjustments can be made originally in the factory, they are difficult to maintain in the field.

Accordingly, one object is to provide a new and improved recording assembly.

Another object is to provide a recording assembly including a new and improved hammer assembly.

Another object is to provide a recording assembly including a novel combination of coded plural bit recording elements and a plurality of slotted hammers with separate striking areas for the code bits.

Another object is to provide a printing hammer having a striking area divided into -a plurality of separate striking surfaces by a plurality of slots which permit movement of the striking surfaces relative to each other during the operation of the hammer.

In accordance with these and many other objects, the present invention is embodied in an accounting machine, such as a cash register, having one or a plurality of type wheels in which each digit representing area is divided into a plurality of code fields selectively pro been adjusted into recording positions.

vided with raised portions in accordance with the coded representation of the digit or data item. These coded arrangements of raised portions provide a binary or other coded representation of the relevent digit and require no more space on the type wheel than a conventional character. When the type wheels have been set under the control of the related unit of accounting equipment, such as a cash register, a hammer assembly is released to strike an interposed record medium and inked ribbon against the type wheel to produce a record that can be photoelectrically or otherwise read by suitable sens-ing equipment.

To insure the printing of a clear and distinct code of uniform density and color, the hammer assembly comprises a plurality of uniplanar elongated hammer elements carried on a pivotally mounted support or bracket at one end. The other end is provided with a slidably inclined portion divided into a plurality of striking surfaces by a number of longitudinally extending slots which impart a degree of spring action to each of the striking surface defining portions of each individual hammer element. The number of striking surfaces is equal to the maximum number of bit representing raised portions in each data representing area, and the striking surfaces on a number of hammer elements are disposed above each of the data representing areas spaced transversely to the direction of adjustment of the type element in alignment with diiferent transversely spaced code fields in a single character representing area.

When a recording is to be made, the bracket or support for the hammers which is normally held in a fixed position against a resilient biasing means is released for movement so that the hammers pivot toward the data representing areas on the recording elements that have During this pivotal movement, the plurality of hammer elements force the record medium and the inked ribbon against the raised portions on the printing elements to record coded representations of the desired data. In view of the fact that the striking area on each hammer element is divided into a plurality of striking surfaces corresponding to the number of bits in the data area and since the striking surfaces are movable relative to each other because of the spring action developed by the slots in the hammer elements, each of the projections on the printing element will be positively struck by a corresponding portion on the hammer element even though the type elements may not be properly centered or aligned and even though the striking angle of the hammer is not correct. In addition, the provision of a group of hammer elements with their corresponding striking surfaces for each of the rows of bit representing raised portions insures that each bit in the selected digit representing area will be sharply and distinctly recorded on the record medium. At the conclusion of the printing operation, the hammer assembly is retracted to its normal position to free the printing elements for adjustment to a subsequent position in accordance with further operations of the accounting machine.

Many other objects and advantages of the present invention will become apparent from considering the following detailed description in conjunction with the drawings, in which:

FIG. 1 is a fragmentary elevational view of a recording assembly embodying the present invention which is shown in a normal position;

FIG. 2 is a fragmentary sectional view of the one of the printing hammers including the assembly shown in FIG. 1 illustrated in a position in which the hammer has just engaged a recording element;

FIG. 3 is a view similar to FIG. 2 illustrating the hammer element at the conclusion of its printing stroke;

FIG. 4 is an enlarged fragmentary end view of the hammer assembly; and

FIG. 5 is a diagrammatic view of a representative code field on one of the recording elements.

Referring now more specifically to FIG. 1 of the draw ings, therein is illustrated a recording assembly which. is indicated generally as and which embodies the present invention. The recording assembly 10 includes a hammer assembly and operating means therefor, indicated gen erally as 12, for selectively recording data in coded and character form on a record medium by striking the record medium and an interposed inked tape against one or more selectively adjustable recording elements 14 in an adjustable recording or type wheel assembly 16. The periphery of each of the individual recording'elements 14 is divided into individual data or digit representing areas, each of which is divided into code fields in which the presence or absence of a raised portion provides a coded representation of the digit.

The hammer assembly 12 includes a plurality of individual hammers 18, a group of which are aligned with the data representing areas on each of the recording elements 14. The striking end of each of the hammers 18 is slotted to form a group of separate and relatively movable striking surfaces which, when the assembly 12 is operated, force the interposed record medium and inked tape against the raised portions on the recording elements 14 to produce the permanent record. Because of the provision of a plurality of recording hammers 18 for each of the digit representing areas and because of the relatively movable striking surfaces on each of the hammers 18, the striking angle of the hammers 18 and the position and alignment of the recording elements 14 does not have to be precise in order to secure clear and distinct coded recordings that can be efliciently sensed by photoelectric reading units.

Referring now more specifically to the adjustable recording assembly 16, the individual recording elements 14 therein can comprise any of the means well known in the art, such as rcctilinearly adjustable type lines or angularly adjustable type wheels. In the recording assembly illustrated in this application, the recording elements 14 comprise type wheels or drums angularly adjustable about the axis of one or more supporting shafts 20. The outer periphery of each of the type wheels 14 is divided into discrete areas representing digits or alphabetical characters which are selectively moved into recording position under the control of an associated accounting machine, such as a cash register.

The type of coding used on the outer periphery of the type wheels 14 can be of any of the ones well known in the art. Preferably, however, this coding arrangement comprises a bar code of the type shown and described in detail in the above-identified copending Sundblad application or in another copending application of Gunner E. Sundblad, Serial No. 845,873, filed October 12, 1959, which application is also assigned to the same assignee as the present invention.

FIGURE 5 of the drawings illustrates a segment of a type wheels 14 on which a coded representation of the digit 2 is provided in the form described in detail in the later filed Sundblad application. The periphery of the type wheel 14 is divided into a plurality of data or digit representing areas 22, one of which is shown in dashed outline in FIG. 5. This data representing area is divided into two peripherally extending rows which are divided into discrete code fields representing different binary values. As an example, the digit representing area 22 shown in FIG. 5 includes a plurality of bit fields 22a-22e repre senting the binary values 1, 2, 8, 4, and a parity check bit, respectively. The bit fields 22a-22e are selectively provided with raised portions in accordance with the digit to be represented.

In the code illustrated in FIG. 5, the presence of a raised portion on the type face indicates the absence of the corresponding binary value. Thus, the digit 2 is represented by placing a raised portion 24 in the area 22a, a raised portion 26 in the area 22c, and a raised portion 28 in the area 22d. This indicates that the digit 2 does not include the binary values 1, 8, and 4, respectively. This code is also arranged for an even parity check and since raised portions are provided in the code fields 22a, 22c, and 22d, an additional raised portion 30 is provided in the parity check field 22e to provide an even number of bits. The raised portion 26 is provided in the configuration of the Arabic character 2 to facilitate reading the printed record. The coded areas 22 representing the other digits can be similarly formed in the manner described in the above-identified copending application.

Referring now more specifically to the hammer assembly 12, the individual hammer elements 18 are carried on a somewhat U-shaped supporting means or bracket 32 which is pivotally mounted on the main frame of the accounting machine by a shaft 34 which also passes through an elongated opening 36 adjacent one end of each of the hammer elements 18. The elongated hammer elements 18 are disposed in a generally parallel relationship resting on the bight of the U-shaped bracket 32 interposed between a pair of upstanding arms or legs 32a and 32b on this bracket. The forward ends of the hammer elements 18 extend outwardly beyond the arms 32a and 32b to be disposed adjacent but spaced above the type wheels 14 of the recording assembly 16.

The outer end of each of the arms 18 is provided with an inclined portion that is divided into three striking surfaces 38, 40, and 42 which, in effect, form the ends of three spring action arms 18a, 18b and integrally formed in the hammer element 18 by two slots 44 and 46 which extend from the outer free end of the element 18 upwardly and then rearwardly toward the supported end of the hammer element 18. If the flexibility of the spring arms 18a-18c should be increased, the inner ends of the slots 44 and 46 can be provided with circular portions or openings 50 (FIG. 2). The three striking surfaces 38, 40, and 42 are so formed as to be aligned with the three code areas 22a, 22e, and 22d, respectively, on the type wheels 14. The hammer elements 18 can be provided with a greater or lesser number of arms similar to the arms 18a-18c in accordance with the number of code fields in each row of the data area 22. Thus, the hammers 18 aligned with the left-hand row of the area 22 illustrated in FIG. 5 would require only two separate striking surfaces rather than the three illustrated in the drawings.

The provision of the separate striking surfaces at the free end of the hammer element 18 insures that each of the raised portions, such as the portions 24, 26, 28, and 30, is separately struck by the hammer, and the relative movement of the surfaces 38, 40, and 42 permitted by the spring action of the arms 18a, 18b, and 180 permits the striking angle of the hammers 18 to be misadjusted without adversely affecting the clarity and definition of the print produced by the type Wheel 14. Excessive movement of the hammer elements 18 relative to each other and to the supporting bracket 32 is limited by a shaft 52 which passes through an enlarged portion of the slot 46 (FIGS. 2 and 3) in each of the hammer elements 18 and is received within aligned and enlarged openings in the legs 32a and 32b of the bracket 32, such as an enlarged opening 54 in the leg 32b illustrated in FIG. 1.

The clarity and definition of the printed record is further improved by providing a plurality of separate hammer elements 18 for engaging each of the code fields 22 on each of the type wheels 14. As illustrated in FIG. 4 of the drawings, the recording assembly 10 includes four separate hammer elements 18 aligned with each of the code areas 22 in printing position. Thus, two hammer elements 18 are aligned with the left-hand row of code fields 22b and 22c (FIG. 2) and two hammer elements 18 are aligned with the right-hand row of code fields 22a, 22a, and 22d. The provision of separate groups of hammer elements 18 for each of the individual type wheels 14 coupled with the freedom of movement of the individual hammer elements 18 relative to each other about the shaft 34 permits the different groups of hammer elements 18 to be pivotally displaced relative to each other to compensate for different alignment and centering of the type wheels 14. As an example, the outer surfaces of the raised portions on the center type wheel 14 (FIG. 4) are recessed below the outer surface of the raised portions on the outermost type wheels 14. However, this does not adversely affect the printing operation in view of the freedom of the center group of hammer elements 18 to move relative to the two outer groups of four hammer elements 18.

To provide means for operating the hammer assembly 12, this assembly includes a lifting and operating arm 56 which is pivotally mounted on the shaft 34 and which is resiliently biased in a clockwise direction about the shaft 34 by a tension spring 58 connected to a pin 60 secured to the arm 56. The pin 60 is disposed within a notch or recess 62 formed in the upper end of the arm 32a of the U-shaped bracket 32. The arm 32a is also connected to a projection 56a on the arm 56 by a tension spring 64 that is connected between a pin 66 on the projection 56a and a pin 68 carried on the arm 32a.

In the normal condition of the hammer assembly 12, the tension spring 58 maintains the pin 60 in engagement with the right wall of the notch or recess 62, and the left wall of this recess is engaged by a depending portion 70a on a latch arm 70 that is pivotally mounted on a supporting structure or frame 72 of the cash register or accounting means by a shaft or pivot pin 74. A tension spring 76 connected between the frame and a pin 78 on the latching arm 70 normally biases the latching arm 70 to the position illustrated in FIG. 1.

When a printing operation is to be performed, the assembly 16 is set and a suitable release mechanism (not shown) included in the cash register pivots the latch 70 in a counterclockwise direction about the pin 74 until the depending portion 70a is moved out of engagement with the left wall of the recess 62. This frees the arm 56 and the bracket 32 for movement in a clockwise direction s about the shaft 34 under the control of the tension spring 58. A pin 80 on the frame 72 limits clockwise rotation of the latch 70 after it is freed. The hammer elements 18 move through the intermediate position illustrated in dashed outline in FIG. 1 to the position illustrated in FIG. 2 in which the striking surface 42 forces the interposed inked ribbon and record medium against the projection or raised portion 28, for instance, in the digit area 22 on the printing wheel 14. However, because of the improper adjustment of the striking angle of the hammers 18, the striking surfaces 40 and 38 do not force the interposed inked ribbon and record medium against the raised portions and 24, respectively. With a conventional hammer element 18, this would result in a blurred record of the binary bits represented by the raised portions 24 and 30 and would result in erroneous interpretation of the record by the photoelectric reading means. However, because of the spring action imparted to the arms 18a and 18b by the slots 44 and 46, the surfaces 38 and 40 are permitted to move relative to the engaged surface 42 and provide a sharp impact forcing the record and the inked ribbon against the projections 30 and 24 in the manner illustrated in FIG. 3. Thus, the formation of the separate striking surfaces 38, 40, and 42 on the illustrated hammer element 18, for instance, and the resilient action of the arms 18a, 18b, and 180 insures the clear and distinct recording of each of the bar bits in the coded representation of the digit or character to be recorded.

In addition, the provision of a plurality of separate hammer elements 18 disposed in transverse alignment with each of the type wheels 14 (FIG. 4) insures that any minor variations in the construction of the hammer elements 18 and the positioning or elevation of the raised portions 24, 26, 28, and 30 in the data representing areas 22 will not adversely affect either the definition or density of the record. As indicated above, the provision of a plurality of separate hammer elements 18 for each of the type wheels 14 permits a clear and definite record of each of the code bar elements to be recorded even though the alignment and centering of the type wheels 14 is not precise.

During the printing stroke, the leading edge of the projection 56a on the arm 56 engages the pin to arrest further clockwise rotation of the arm 56 about the axis of the shaft 34. The record supporting bracket 32 is free to continue its movement in a clockwise direction about the shaft 34 by elongating the tension spring 64 which serves to damp vibrations arising from arresting movement of the arm 56. The left edge of the notch 62 engages the pin 60 to limit clockwise rotation of the bracket 32 following the termination of the pivoting movement of the arm 56.

At the conclusion of the printing stroke, the tension spring 64 pivots the bracket 32 in a counterclockwise direction until the pin 60 again bears against the right edge of the notch 62, the arm 56 being held in a fixed position by the stronger tension spring 58 holding the projection 56a in engagement with the pin 80 on the frame A return mechanism (not shown) included in the cash register then pivots the arm 56 in a counterclockwise direction about the shaft 34 which is effective through the engagement of the pin 60 with the right edge of the recess 62 to pivot the bracket 32 and the elements carried thereon in a counterclockwise direction. The adjacent portion of the arm 32a of the bracket 32 cams against the latch 70 to pivot this latch in a counterclockwise direction about the pin 74 to permit the depending portion 70a to move into interlocking engagement with the notch 62.

This secures the hammer assembly 12 in its normal posi tion until the next recording operation is to be performed.

Although the present invention has been described with reference to only 'a single illustrative embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A printing assembly for use with type wheels having separate character recording areas comprising a hammer structure, means pivotally mounting the hammer structure adjacent one end, and a plurality of end portions formed integral with the hammer structure adjacent the opposite end of the structure and adapted to force a record medium against a single character recording area on the type wheel, each end portion being formed in an edge surface of the hammer structure by a slot in said hammer extending from the end portion to a position adjacent the pivotally mounted end of the hammer structure.

2. A printing hammer for use with a recording element comprising a substantially uniplanar and elongated hammer element having an inclined end portion, and a plurality of separate striking surfaces formed in an edge of the inclined end portion of the hammer element by at least one slot extending through the hammer element from an open end in the inclined end portion to a closed end spaced rearwardly along the elongated hammer element from the inclined end.

3. The printing hammer set forth in claim 2 including an enlarged opening formed in the slot to increase the freedom of movement of the striking surfaces relative to each other.

4. A printing hammer assembly for use with printing elements comprising a plurality of substantially uniplanar hammer elements disposed in generally parallel positions spaced from each other in a direction transverse to the planes of the hammer elements, means pivotally mounting the hammer elements with portions of the elements disposed adjacent the printing elements, and means dividing the edges of the adjacent portions of the elements into a plurality of striking areas including slots formed in the hammer elements extending inwardly from the striking areas a distance sufiicient to permit movement of the striking areas relative to each other and to the hammer elements when the printing elements are struck.

5. The printing hammer assembly set forth in claim 4 including stop means adapted to engage the hammer elements to limit movement of the hammer elements toward the printing elements.

6. A printing hammer assembly for use with printing means comprising a plurality of uniplanar hammer elements disposed in a generally parallel relation, means mounting the hammer elements for pivotal movement about an axis extending generally transverse to the planes of the elements, and a plurality of spring finger portions formed integral with each of the hammer elements and terminating in strike portions adapted to strike the printing means, said spring finger portions being defined by slots in the hammer elements extending inwardly from the strike portions a sufficient distance to permit movement of the spring finger portions relative to each other.

7. A printing hammer assembly for use with recording elements comprising a movably mounted supporting means, a plurality of uniplanar hammer elements mounted on the supporting means in a parallel relation with their end portions projecting outwardly beyond the supporting means to a position adjacent the recording elements, and a plurality of separate striking areas integrally formed in the edges of the end portions of the hammer elements by a plurality of slots which permit relative movement between the striking areas.

8. The printing hammer assembly set forth in claim 7 in which the hammer elements are elongated and in which the slots extend longitudinally relative to the hammer elements and include oifset portions adjacent the striking areas.

9. The printing hammer assembly set forth in claim 7 including stop means carried on the supporting means and engaging the hammer elements to limit movement thereof.

10. A printing assembly comprising printing means having a number of data representing areas each divided into a plurality of code fields, a plurality of hammer elements, means mounting the hammer elements adjacent the printing means for edgewise movement toward and away from the printing means, and a plurality of separate strike portions on the edge of each of the hammer elements disposed adjacent diiferent ones of the code fields in'one data representing area, said separate strike portions being formed by slots in the hammer elements extending inwardly from the strike portions to permit relative movement between the strike portions on the same hammer element.

11. A printing assembly comprising printing means having a number of data representing areas each divided into a plurality of code fields, a plurality of hammer elements, means movably mounting the elements adjacent the printing means with portions on more than one hammer element disposed to strike a given data representing area,

and a group of separate striking means formed in each of the portions for striking different code fields in the same data representing area, the separate striking areas on each of the hammer elements being formed integral with the related hammer element and being defined by slots permitting movement of the striking areas relative to each other.

12. A printing assembly comprising adjustable printing means having its surface divided into a plurality of data representing areas, each of said areas including a data representing arrangement of projecting portions, a hammer assembly including a plurality of generally uniplanar hammer elements, means mounting the hammer elements for movement toward and away from the printing means in a direction transverse to the direction of adjustment of the printing means so that the edges of the uniplanar elements move toward and away from the printing means, and a group of separate striking means formed in each of the hammer elements for striking the project ing portions in the same data representing area, the separate striking areas on each of the hammer elements being in the edge of and integral wnth the related hammer element and being defined by slots permitting movement of the striking areas relative to each other.

References Cited by the Examiner UNITED STATES PATENTS 1,373,545 4/21 Wiegman 101-21 1,467,191 9/23 Ormsby 19723 1,716,699 6/29 Kirkegaard 101-32 2,127,897 8/38 Watkins 101--297 2,405,562 8/46 Ellerbeck 10l109 X 2,928,896 3/60 Dirks 178--34 WILLIAM B. PENN, Primary Examiner. 

1. A PRINTING ASSEMBLY FOR USE WITH TYPE WHEELS HAVING SEPARATE CHARACTER RECORDING AREAS COMPRISING A HAMMER STRUCTURE, MEANS PIVOTALLY MOUNTING THE HAMMER STRUCTURE ADJACENT ONE END, AND A PLURALITY OF END PORTIONS FORMED INTEGRAL WITH THE HAMMER STRUCTURE ADJACENT THE OPPOSITE END OF THE STRUCTURE AND ADAPTED TO FORCE A RECORD MEDIUM AGAINST A SINGLE CHARACTER RECORDING AREA ON THE TYPE WHEEL, EACH END PORTION BEING FORMED IN AN EDGE SURFACE OF THE HAMMER STRUCTURE BY A SLOT IN SAID HAMMER EXTENDING FROM THE END PORTION TO A POSITION ADJACENT THE PIVOTALLY MOUNTED END OF THE HAMMER STRUCTURE. 